Billet piercing apparatus



J. F. CRAWFORD BILLET PIERCING APPARATUS March 13, 1951 6 Sheets-Sheet 1Filed April 28, 1945 BY M 9 y 51% J. F. CRAWFORD BILLET PIERCING APPARATUS March 13, 1951 6 Sheets-Sheet 2 Filed April, 28, 1945 INVENTORMarch 13, 1951 J. F. CRAWFORD 2,545,229

BILLET PIERCING APPARATUS Filed April 28, 1945 6 Sheets-Sheet 3 '7 j a Rm r 'm'" .2 ump I I E l l INVENTOR ATTORNEY March 13, 1951 J. F.CRAWFORD BILLET PIERCING APPARATUS Filled April 28, 1945 6 Sheets-Sheet4 ATTORNEY I I JR I W 7% March 13, 1951 J. F. CRAWFORD BILLET PIERCINGAPPARATUS 6 Sheets-Sheet 5 Filed April 28, 1945 Mm 2 WW, QM

arch 13, 1951 J, F, CRAWFORD 2,545,229

BILLET PIERCING APPARATUS Filed April 28,- 1945 6 Sheets-Sheet 6Patented Mar. 13, 1951 BILLET PIERCIN G APPARATUS John F. Crawford,Racine, Wis., assignor to J. I. Case Company, Racine, Wis., acorporation of Wisconsin Application April 28, 1945, Serial No. 590,896

2 Claims. (01. 789) The present invention relates to a forgingapparatus, and an object thereof is to generally improve theconstruction of such mechanism. A further object is to provide anapparatus for forming a round forging from an angular billet. A furtherobject is to avoid the formation of a claw-like appendage at the end ofthe billet. Further objects are to provide an apparatus for forming around hollow forging from an angular billet in one heat and for causingan improved flow of metal in such a forging so as to improve the grainstructure in the resulting forging. Further objects are to provideexpedients for the realization of the above objects.

Other objects and advantages of the invention will become apparent froma consideration of the following detailed description taken inconnection with the accompanying drawings wherein a satisfactoryembodiment of the invention is shown. However, it is to be understoodthat the invention is not limited to the details disclosed but includesall such variations and modifications as fall within the spirit of theinvention as herein expressed.

In the drawings,

Figure 1 is a plan view partly diagrammatic in character of anapparatus.

Fig. 2 is a vertical sectional view on the line 2-2 of Fig. 1.

Fig. 3 is a horizontal sectional view onthe line 3--3 of Fig. 2 on asomewhat reduced scale.

Fig. 4 is an enlarged detail of a portion of Fig. 1.

Fig. 5 is an elevation of the portion of the machine shown in Fig. 4.

Fig. 6 is an enlarged vertical section substan tially on the line 66 ofFig. 4.

Fig. '7 is a right end elevation (enlarged) of the structure seen inFig. 5 with parts broken away.

Fig. 8 is an enlarged vertical sectional view substantially on the line8-8 of Fig. 5.

Fig. 9 is an enlarged vertical sectional view on the line 9-9 of Fig. 4.

Fig. 10 is an enlarged vertical sectional view on the line Ill-l0 ofFig. 8.

Fig. 11 is an enlarged plan view of certain mechanism indicated in Fig.1.

Fig. 12 is a side elevation of the same.

Fig. 13 is a diagrammatic representation of a billet in the variousstages of the operation of forming a hollow object therefrom, thevarious stages being designated as a to g inclusiveand parts beingbroken away.

Fig. 14 is an end view of the billet prior to the forming process, asindicated by the line MM in Fig. 13.

Fig. 15 is a view of the billet taken on the line l5l5 of Fig. 13.

Fig. 16 is an enlarged sectional view on the line |6 I6 of Fig. 15.

Fig. 1'7 is a view taken on the line lll 1 of Fig. 13 showing the hollowobject nearly completed.

Fig. 18 is a view taken on the line l8-l8 of Fig. 13 showing thecompleted object.

The invention may be best understood in a preliminary way by aconsideration of Fig. 1. The billets which are to be forged are heatedin a furnace F, being delivered to a feed plate 25 in any suitablemanner forming no part of the invention and not necessary to describefurther. A gripping and handling unit generally designated as 26 is usedto place the cool billets in furnace F and also to remove heated billetsand place them in a pointing and descaling unit generally designated asP. The billets are cleaned of the scale acquired in the furnace,partially pointed and rolled into a substantially round or cylindricalform in the unit P and then delivered into a transferring and invertingunit T by which they are transferred to and placed within a forging dieunit generally designated as D where the billet is formed into a hollowobject of the desired form, in the present instance a shell blank. Theseveral operations take place in quick succession, the elapsed time fromthe placing of the billet in the unit P to its removal from the unit Dbeing commonly in the neighborhood of not more than seconds. For thisreason, it is possible to perform the several operations which will bedescribed in detail presently, while the billet retains the heat whichit had when first removed from furnace F. In other words, it isunnecessary.

to reheat the billet once the cycle of operations is started. This, ofcourse, reduces the loss of metal by oxidation and also greatly reducesthe amount of handling as compared with any process in which reheatingof the billet is required between the steps of the method. It iscommonly more convenient for forged objects of the nature dealt with inthe present invention to obtain material of angular formation, in thepresent instance square, the billets dealt with in this case havingapproximately the cross section indicated in Fig. 14, namely square withrounded corners- For making a round hollow object, the billet must bebrought to a substantially round outer configuration and then pierced.The apparatus which applicant has devised will now be described in themost convenient and efiicacious manner.

The furnace F is of a well-known type having a floor 21 which rotatesvery slowly in the direction indicated, the temperature within thefurnace being maintained at the desired high level by any well-knownmeans not necessary to describe. Handling unit 26 is in the nature of aremote control pair of tongs having handle grips 28 and a long pole-likebody 29. Portion 29 is pivotally supported from a trolley 30 freelymovable on rails 3| and 32 which are to be understood to be located wellabove the head of an operator manipulating grips 28. Portion 29 issubstantially balanced and pivotallysuspended beneath trolley 35 and has-a claw-like jaw unit 33 which can be opened and closed by suitable con;trol means in the neighborhood of grips 28. A shield 34 protects theoperator from the intense radiations from within furnace F. Bymanipulation of grips 28, cold billets as C may be lifted by jaw 33 andplaced within furnace F on floor 21. In the course of time floor 21 willhave substantially completed a revolution, whereupon the billets willappear at H in a highly heated condition.

Unit 26 is also manipulated to grip heated billets and remove them fromfurnace F. It will be understood that suitable controls, not necessaryto describe, are associated with unit 25 and that the parts aresuitablycooled by internal circulation of water, etc., so as not to be damagedby the heat of the furnace. Unit 25 is readily moved in and out andswung from side to side so as to keep furnace F charged with billetsbeing heated and to remove heated billets as fast as necessary to supplythe forging process.

It will be understood that suitable shields and the like are associatedwith the mechanism to protect the operators and make working conditionsas comfortable as possible, most of these being omitted to avoidobscuring the essential features of the invention.

In operation the unit 26 is manipulated to pick up one of the hotbillets H and is then swung to position the billet over a holder 35.Turning to Figs. 4 and 5, holder 35 comprises an upright box likereceptacle which is open at both ends. Unit .25 is then manipulated torelease the billet which drops into holder 35 and rests on an abutmentplate 36. A retainer tongue 31 extends partially beneath the billet andserves to prevent the latter from dropping out of holder 35. Plate 35 issupported in any suitable manner, as from a frame member 38, other framemembers as 39, 45, 4|, etc., being united to provide a base forsupporting the several operative parts incorrect relation.

Holder 35 is carried on a swinging arm 42 pivoted at 43 on a suitablebearing carried by frame members 39 and 4|. Arm 42 may swing from thefull line position of Fig. to the dotted line position therein, therebycarrying holder 35 and billet H into position for a preliminaryoperation.

The preliminary rounding of the billet is accomplished by forcing itthrough a roller set generally designated as 44 which as best seen inFig. 7 comprises rollers 4545, journaled on pins as 45 carried in ayoke, ring or plate member 41, bushings as 48 being introduced, ifdesired, where the rollers run on the pins. The configuration of rollers45 is such as to form a substantially round opening therebetween,whereby a billet forced through the space between the rollers will becompressed into substantially round form.

Billet H is forced between the rollers in the present instance by a ram49 so that rollers 45 are rotated by contact with the moving billet. Inthis type of operation in the past, the rollers have displacedbackwardly some of the metal of the corners which would overhang therear face of the billet and form a pronged claw-like extension whichwould be objectionable. Furthermore, difficulty might be expected fromresistance of the billet to entering between rollers 45." Thesedifficulties are obviated by the use of the pointing operation abovereferred to.

A set of dies generally designated as 50 is 4 provided and which may beswung into and out of the path of plunger 49, for example by means of afluid cylinder 5|. Pointing unit P includes the above mentioned dies anda pair oftension rods 52 and 55 which are united with yoke 41 by nuts 54and 55. Rods 52 and 53 serve to hold some of the operative parts incorrect relation with each other, in the present instance die member 55being mounted on rod 53. A sleeve 55, Figs. 4 and 5 is slidablyjournaled on rod 53 and has a bracket portion 51 supporting a die 58which is provided with a cavity 59, as best seen in Fig. 9. A similardie 60 is slidably supported on rods 6| and 52 supported from bracket 51and die 59 is forced away from die 58 by springs 53 and 64. Dies 58 and50 are therefore held apart sumciently that holder 35 with billet Htherein can be introduced between them by swinging of arm 42. Bracket 51is urged to the left as seen in Figs. 4 and 5 by a spring 65. Inoperation, bracket 51 is swung downwardly about rod 53 after which arm42 is swung to the dotted position indicated in Fig. 5. Holder 35 thenbeing horizontal, billet H will remain therein and tongue 21 will beswung upwardly about a pivot 55 by means of an abutment 56a, suitablysupported on the machine. Pivot 55 passes through the horizontal portionof arm 42 and is also supported by a bracket 55b extending from arm 42,and tongue 31 has an arm 650 connected by a spring 55d to a point on arm42. Spring 55d yieldingly maintains arm 550 against a stop 65c and thusmaintains tongue 31 in position to prevent billets from passing throughholder 35. When holder 35 takes the dotted position of Fig. 5, finger 31is pushed out of the way by abutment 65a, so as to clear what waspreviously the lower end of holder 55. Bracket 51 is then swung upwardlyby means of cylinder 51 so as to position dies 58 and 65 at oppositeends of holder 35 and billet H. Ram 45 is then advanced into contactwith die 58. The resulting pressure of ram 45' compresses spring 55 andallows bracket 51 to shift into contact with ring 41 which, as abovestated, is anchored to above mentioned rods 52 and 55. Pressure of ram49 also compresses springs 63 and 54 so as to bring die 55 against oneend of billet H and also to force the other end of billet H into die'58. Bracket 51 is supported by yoke 41 against further movement and thepressure of ram 4-5 accordingly presses billet H intothe cavity 55 ofdie 58 and into a corresponding cavity 58a in die 68. This action bevelsthe ends of the billet and the pressure also upsets the billet or causesit to swell somewhat with a corresponding reduction of its length. Thisupsetting or swelling causes most or all of the accumulation of scale,which is brittle-to break and fall off the billet. Ram 49 is thenretracted whereupon die 55 is forced away from the billet by springs 53.and '54. The billet is unseated from die 58 by means of a fluid pressedcylinder 65a whereupon die set 56 is swung downwardly about rod 53 outof the way of plunger 49, leaving billet H resting in holder 35. Owingto the pointing, beveling or chamfering of the forward end of thebillet, it will enter readily between rollers 45 and furthermore, if thematerial of the corners is forced backwardly somewhat by the rollers, itwill merely fill out the corners which were chamfered by the rear die 60so that the rear face of the billet will be approximately fiat andsquare after the rolling operation.

Returning to a more detailed description of the construction of theapparatus, ram 49 is actuated 8! whenever a billet is pressed into die58.

by a plunger 68 reciprocable in a cylinder 89 supported on members 38,39, 48, etc., and having a flange 18 in which above mentioned rods 52and 53 are anchored as by means of nuts I! and 12. Therefore, thereaction of the pressure of ram 48 on cylinder 69 is transmitted to andcounteracts the reaction in the opposite direction exerted in ring 47 bybillet H passing between rollers 45. Plunger 6.8 is actuated in thepresent instance by hydraulic pressure from any suitable or well-knownsource not necessary to describe and is retracted when desired byplungers I3 and I4 reciprocable in cylinders I5 and I8. Plungers 73 andI4 connect as by pull rods IT-TI with a cross head I8 engaging plunger68.

Arm 42 is swung by the action of a ram 19 reciprocable in a cylinder 88and actuating a rack 8I engaging a sector 82 rotatable about pivot 43and fixed with arm 42. A guiding device 83 maintains rack 8| in drivingrelation to sector 82.

Cylinder 5| is pivotally connected at 84 with a bracket 85 fixed in thepresent instance in relation to yoke 41 and has a bifurcated connection88 with a portion of bracket 51. Reciprocation of portion 88 caused bycylinder 5| will therefore cause swinging of bracket 51 in a generallyup-and-down direction about rod 53.

'It is to be understood that suitable piping and controls are providedfor actuating the several rams in proper sequence and they arepreferably provided with interlocking means in well-known manner toprevent inadvertent actuation of any one of the rams at the wrong time.These controls being well-known in general and forming no part of thepresent invention, it is considered unnecessary to unduly complicate theshowing by describing them further.

Above mentioned cylinder 85a comprises a caplike member reciprocablyfitted in a fluid-tight manner on a stationary piston 8'8 fixed inrelation to bracket 51. Piston 81 is hollow and connected by means of apassageway 88 with a source of fluid under pressure, represented by aflexible connection 89. A valve 88 disposed within piston 81 is seatedabout an outlet port 8! and has a stem 92 fixed with cylinder 85a.Cylinder 85a extends slightlpy beyond a position flush with the face ofdie 58. As will be seen, pressure in passageway 88 will tend tocontinuously maintain cylinder 85a as far as possible to the left asseen in Fig. 9, valve 98 closing port 9| and relieving the fluid tightjoint between cylinder 65a and piston 81 of pressure except whenactually working. It is to be understood that the pressure of billet Hinto die 59 is substantially in excess of the pressure of cylinder 65aso that cylinder 85a is forced to the right causing opening of port Aplurality of perforations 93 extend through cylinder 85a so as to exposethe end of billet H to fluid under pressure from the interior ofcylinder 650.. This fluid, commonly cold water, immediatelydisintegrates and washes away scale on the end of billet H. However, thewater is so small in amount and the duration of the flow is so shortthat no material cooling of the billet is effected. The clearing of thisend of the billet of scale is important since it is this end which willbe exposed to the piercing punch as will appear.

In the retracting movement of arm 42 and holder 35, tongue 3'! isrestored by spring 66d to position to prevent a billet from falling outof the holder when the latter is again moved.

Bracket 5! when moved downwardly, as shown in dotted lines in Fig. 6,presents a -V-shaped 6 channel 94 in the path of billet H and whichserves to guide the latter between rolls 45 and to insure properstarting of the billet therein. Ram 48 is.

again advanced, this time directly against the rear surface of thebillet which is forced over support 94 and between rollers 45. Anyremnants of scale remaining on the corners of the billet would be forcedinto the surface and accordingly a plurality of scraper blades 95 isprovided pivoted on plate 96 carried on above mentioned yoke 41. Bladeshave sharpened inserts 9'I91 which serveto scrape the corners of thebillet immediately before they pass between the rollers. In this way thehot metal is substantially entirely clean when it passes between therollers and no scale is rolled'into the material. Blades 85 are pivotedas at 98 and pulled inwardly by springs 89 so as to insure contact withthe billets and allow reasonable variation in size without difficulty.Plunger 48 forces billet H entirely through yoke 41 between rollers 45,the, billet falling into a receptacle I88. It is to be noted that theend of billet H which was cleaned by fluid from perforations 93 isdisposed at the bottom of the receptacle I88.

Receptacle I88 is partially open at the bottom as seen in Fig. 12 buthas a lip I 8I which extends inwardly sufficiently to prevent a billetfrom dropping entirely through the receptacle. the major portion of thereceptacle is open at the bottom as indicated. In this manner, any scalewhich may still be dropping from the billet is eliminated at this point.Receptacle I88 is fixed at the end of a swinging arm I82 fulcrumed atI83 on a stand I84 of any suitable construction, arm I82 being capableof swinging from the full line to the. dotted line position in Fig. 12.It is to be noted that receptacle I88, in the dotted position, isinverted in relation to its full line position. As arm I82 swings,billet H will be brought first to a horizontal position and then to aninverted position. In the progress of this movement, the billet willshift from contact with lip I8I and rest on a retaining tongue I85.Tongue I85 is swingable on a pivot I86 on receptacle I88 and controlledby,

a hand lever I87. As seen in Fig. 11, tongue I85 has been swung clear ofthe entrance to receptacle I88. However, when arm I82 approaches avertical position, tongue I85, due to the preponderence of weight oflever I81 thereover, will swing to the dotted position in Fig. 11,thereby preventing billet H from dropping out of receptacle I88prematurely. When the billet shifts away from lip I8I, it is caughtandrests against tongue I85 so as to be supported in position above a dieunit generally designated as I88, constituting part of above mentionedforging die unit D. By this means, the preliminarily rounded billet ispromptly transferred to a convenient position to enter die unit I88 andis inverted so that the cleaned end is uppermost in preparation for thepiercing operation.

When it is desired to place the billet in die I88, lever I8! is swung toa position corresponding to that shown in Fig. 11, whereupon the billetdrops out of receptacle I88 into die I88 as will be further explained.Arm I82 is then returned to the,

full line position of Fig. 12, ready to receive another. billet. As armI82 approaches said full line position, lever I81 encounters theinclined face of a cam I88 fixed with a frame member I I8, constitutingpart of stand I84 and is automatically swung from the dotted to the fullline position so as not to interfere with placing of another 75 i letxi. l pta ,I 11., v

However,

Arm I 92 preferably carries a counterbalance weight IIItosubstan-tia-lly counteract the very considerable weight-of receptacleI-Iiuand-its-contents and. the. arm is actuated-- in the presentinstance bya plunger I I2: driven by fluid pressure ina cylinder II3-anchored at I -I-4- to stand H14. Plunger 2'. has aracls Il-5-engaging agear II-6 fixed with arm I92, a guiding-device- III serving to maintainrack H5 in proper relation to gear Pressure fluid for cylinder I I3 iscontrolled by well-known means not necessary to: describe as formingnopart of: the present invention. Sufiicient to. say; suitableinterlocking elements are provided so: as to make itv impossible for abillet Die H9 comprises a sleeve-like element supported in acastingmil-having an inwardly tapered ring: I 2 I at one end and ashoulderedring I:22 at the other.

Die H8 is supported in a casting I23 and the description-of one willsufiice for the other. ings I and W3 are slidably supported ina diecarrier I24 which isoscillatable about apost I25 carried: on the bed I25of a powerful hydraulic press-of well-known form forming nopart. of. thepresent-invention. The press has anupper plate on head: I21 which may bedriven downwardly with heavy pressure to a predetermined point indicatedin. dottedlines in Fig.2..

Thehot. billet dropped into either die. H8 or.

H9 lodges near the bottom of the die in the.

tapered ring IZI'. Die carrier I24 is then oscillated 180 fromthepos-ition shown-inFig 1 until oneof dies H8 or I I9 occupiestheposition shown for die I19. A ram= I28 is then moved upwardly,

as will appear, and raises billet H to a point substantiallyflushwiththe top of ring I22. Head I2? thendescends and a punch I29 entersring I22 and commences to pierce billet" H which is prevented fromdescending by rain I28.

The entrance of punch I 29 spreads billet H tothe extent permitted byring I-22. This is illustrated inF-ig. 13-6. The upper end of billet His therefore anchored to shouldered ring I22; As

head I21 continues to descend, punch I29-t'hrusts deeper into billet H,spreading the metal against die H9 and stretching the resulting sidewalldownwardly between itself and shouldered ring I22. The pressure on punchI29 is resisted byram I28, pressing on the bottom of billet H to acertain point in the travel of punch I29; beyond which ram I28 descendsbut at a slower rate than punch I29. In this way, the pressure of punchI29 is divided between piercing and spreading the material of billet Hagainst die I I9 and stretching the resulting side wall downwardly fromshouldered ring I22. to the limit of movement possible in head I27;

the Various stages of formation of the blank being-indicatedat d, e, fand g in Fig. 13. During the course of the downward stroke of punch I29;the metal is forced intoa recess I30 in' ram I28-to-form-a centeringboss on the object; Sub"- stantia-lly any desired configurationoftheobject at this end can be obtainedby suitably forming ring l2I and thehead I3I of ram I28; The-forg Cast- Punch I29 descends ing process isthus complete in one heating of the billet and in one stroke of thepress;

Assoon as stage g, Fig. 13-, i reached, head IT! is raised. The forgedobject, tending to follow punch I29 encounters a ring: I32 in a stripperplate I33 anchored to bed [26. therefore forcibly withdrawn from theforging which-remains in the die. Ram I28- being in its loweredposition, die carrier I24 is again oscillated until the die carrying theobject is returned-- to the'loadingpoint, seen in Fig. 2". Herea ram I34is pressed upwardly intothe die and raises the forged objectsubstantially into the position shown in dotted lines. Any suitablemeans is employed to transmit the object to asuitable place to be cooledand further processed.

It will be understood that while the above=de-- scribed operationsaretaking place in one die as H 8, 2; corresponding series ofoperationsis taking place in die H9, one die being unloadedand again loaded duringthe period that ablank is'being formed in the" other die.

Punch I29 receives considerable heat from the metal being processed andcannot be used repeatedly without proper treatment. Accordingly, aplurality of additional punches I35; I36, I31, I39 and I59 is provideddepending from arotat able plate I iil journaled on a' stem I4I' rigidlyattached to plate I2l". The whole assembly descend 'with head I2? andafter each operation,

plate I49 is rotated sufficiently to bring a new punch in line with ringI32 in stripper plate I33. In the situation shown, punch- I29 is aboutto perform a forging operation; Punch #35; which 1 ha just been used andis heated will descend a-t oneside of die carrier I24 into a tank orvat. I42 in which is retained a body of cooling and lubricating fluidI43. I21 immerses several of the punches in fluid I43' preparatory to asubsequent punching operation. By the time any one punch comes intopositionto forge a blank, it has been thoroughly cooled and coated withthe necessary lubricating material;

Plate I 38 is rotatedasbest' seen in Fig. 1 by a hydraulic cylinder I44pivoted to. a portion of head E21; Cylinder I44 hasa ram I'45'having apawl I48. engaging a series of notches as I41. Cylinder I44 is swungtowards plate I by a spring I48.

At the conclusion of each. turning movement of plate I49, a detent I49engages one of the several punches, being yieldably pressed thereagainst by a spring. I59 and resting against a stop I5 I. Inthis manner,it is assured that plate I46 will. be held in the proper position forits working stroke. Detent I49 is swung outwardly by suitable orwell-known mechanism to clear plate Hillin its downward movement.

Plate I 49 has a stem I5Ia reciprocable in a.

guide I52- which. is fastened to a registering plate I53. Guide I52rests on a plate I54 supported by a. carrier I55 from stem I5'I'.. Thus.upon downward movement of head I251, plate I53 also descends to theextent permitted by stripper plate It'd Plate I53 carries a seriesofpins I56 in. the presentinstance spaced equally between punches I29.I35, etc; Pins I56 shortly prior to entering of any punch into anybillet H pass through registering holesas I 57 in stripper plate I33 andenter locating holes I58 in die carrier I 24. In'this manner; thedies'are accurately registered with the punches before. the punchesenter the billets.

Punch I29 is Repeated'strokes of head.

Die carrier I24 is oscillated by a gear I59 engaged by a rack I60 drivenby a fluid pressure cylinder I6I of well-known type not necessary tofurther describe.

The pressure of punch I29 both downward and upward when being removedfrom the forging, is very substantial. For this reason, bearings I6Iaand I62 of die carrier I24 are protected from these forces. The weightof the die carrier is supported by pressure fluid in a cylinder I63having a piston I64 which rests on post I25. The fluid, in the presentinstance air, raises'die carrier I24 against stop nuts I65. Downwardpressure of punch I29 overcomes the pressure in cylinder I63 untilcasting I20 rests on a collar I66 solidly supported on bed I26 andforming part of the mechanism of ram I3I. Thus, bearings I6I and I62 arerelieved of downward pressure. When punch I29 is being pulled out of theforged object, carrier I24 is again raised by the fluid pressure againststop nuts I 55 but casting I20 is further raised until ring I22 restsagainst stripper plate I33 so that the upward pressure is taken by plateI33 and not by carrier I24.

Ram I28 is raised by a piston generally designated as I61 operating in acylinder I68. Pressure fluid is supplied through a pipe I69, acontinuation I10 of which extends to within a short distance of cap I3I.Pipe I10 clears a bore 11! so that pressure fluid supplied throughextension I10 passes through cap I3I and returns through bore "I to theunderside of piston 561. A considerable volume of fluid thus passesimmediatel beneath cap I3I during rising and falling movement of ramI28. In this manner, cap I3I is prevented from overheating. Casting I isprovided with grooves as I 12 to which cooling fluid, in the presentinstance water is supplied as for example by a hose connection I13. Thefluid is confined in grooves I12 by means of a jacket I14 and passesfrom one groove to another, being finally exhausted through a pipe I 15.Dies II 8 and H9 are thereby prevented from being overheated anddestroyed by the heat of the billet being forged.

Ram I34 has a claw-like lifting element I16 which engages the bottom ofthe forged object. Since the engagement with the hot forging ismomentary only, element I16 is adequately cooled by the surrounding air.A slotted opening I11 is provided for connection I13 to provide freedomfor raising and lowering of casting I20.

I18 is a circulating pump which keeps the fluid I43 sufiicientlyagitated for effective cooling of punches I35, etc.

The operation of the mechanism is thought to be adequately clear fromthe foregoing description, the billet being pointed and upset inmechanism P where most of the scale drops off. It is then pressedthrough roller set 44, the corners being scraped by blades 95immediately before being acted upon by the rollers. The billet isimmediately inverted, by transfer unit T and placed in a forging diewhere it is pierced while being supported partly from beneath and partlyfrom above by shouldered ring I22. In

this manner the complete hollow object is forged a billet and form itinto a substantially cylindrical hollow object, the combination of abed, a rotatable die element mounted on the bed, a punch, means forsupporting the punch and advancing it toward the bed for piercing abillet, a plurality of dies supported by said die element and movableselectively by rotation thereof from a position registering with saidpunch, to a position removed from said punch, a stripper member rigidwith the bed, and disposed adjacent said die element, and a locating pinmovable with said punch and engageable with said stripper member andwith said die element for accurately locating said die in registrationwith said punch preparatory to a piercing operation.

2. In a forging machine adapted to receive a billet and form it into asubstantially cylindrical hollow object the combination, of a bed, arotatable die element mounted on the bed, a punch, means for supportingthe punch and advancing it toward the bed for piercing a billet, aplurality of dies supported by said die element and movable selectivelyby rotation thereof from a position registering with said punch to aposition removed from said punch, a stripper member rigid with the bedand disposed adjacent said die element, and a plurality of spacedlocating pins movable with said punch, a plurality of said pins engagingat spaced points with said stripper member and with said die element foraccurately locating said die in registration with said punch preparatoryto a piercing operation.

JOHN F. CRAWFORD.

REFERENCES CITED The following references are of record in the file ofthis patent:

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